Gabriel, I wasn't kidding when I wrote that marking gauges are the number one measuring devices. I have a few
I do have a few Starrett 12"/300mm combination squares. I purchased them all on eBay quite cheaply about 20-odd years ago. Very nice, but they are not used for laying out parts. I do use the blades as straight edges and as rulers.
I am more likely to use this Veritas Sliding Square, since it works more like a marking gauge (in fact, that is often how I use a Starrett 6" double square - that is a very useful square)
More commonly used are these square: 4" and 6" double square. Starrett, Vesper, and Moore&Wright ..
These are for joinery ...
6" and 9" Vespers ...
Note that none of the square have graduations. They are for marking, not measuring.
Another marking tool is a set of dividers ...
If you need a tape, get a small one - 3m is enough. Festool and BMI ...
Below are drawer panels for stopped dados ...
They are set out with templates/story sticks ...
(Incidentally, I later ripped out the dividers as the grain rain thee wrong direction - how I missed this at the start, I do not know).
The point I want to make is that good rulers are important, but a method that offers repeatability without measuring is even better. This is equally valid for power- and hand tools.
Regards from Perth
Derek